RU2739375C2 - Aerosol-generating article with insulated heat source - Google Patents

Abstract

FIELD: liquid atomisation or spraying devices.

SUBSTANCE: invention relates to aerosol-generating article (2) which contains aerosol-forming substrate (4), a combustible heat source (3) and at least one layer of ceramic paper (5), surrounding at least part of length of combustible heat source (3). Product (2) further comprises one or more airflow paths, which enable air to be drawn in through aerosol-generating article (2) for inhalation by the user; and one or more incombustible substantially air-permeable partitions between combustible heat source (3) and aerosol-forming substrate (4).

EFFECT: disclosed is an aerosol-generating article with an insulated heat source.

17 cl, 5 dwg

Description

The present invention relates to an aerosol generating article comprising an aerosol forming substrate and a combustible heat source, and to a method for making such an aerosol generating article.

A number of aerosol generating products have been proposed in the prior art in which tobacco is heated rather than burned. One purpose of such “heated” aerosol generating articles is to reduce the known harmful smoke constituents resulting from the combustion and pyrolytic decomposition of tobacco in combustible cigarettes. In one type of heated aerosol generating article, an aerosol is generated by transferring heat from a combustible heat source to an aerosol generating substrate adjacent to the combustible heat source. During aerosol generation, volatile compounds are released from the aerosol-forming substrate by heat transferred from a combustible heat source and entrained in air drawn in through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol that is inhaled by the user.

The combustion temperature of a combustible heat source for use in a heated aerosol generating article should not be so high as to cause combustion or thermal decomposition of the aerosol forming substrate during use of the heated aerosol generating article. However, the combustion temperature of the combustible heat source must be high enough to generate sufficient heat to release enough volatiles from the aerosol-forming substrate to form an acceptable aerosol, especially during the first puffs.

A number of combustible heat sources have been proposed in the prior art for use in heated aerosol generating articles. The combustion temperature of combustible heat sources for use in heated aerosol generating articles is typically 600 ° C to 800 ° C.

It is known to wrap an insulating element around the periphery of a combustible heat source of a heated aerosol generating article in order to reduce the surface temperature of said heated aerosol generating article. However, it has been found that such insulating elements are capable of lowering the temperature of a combustible heat source during combustion of that combustible heat source, potentially reducing the efficiency of the heat source in heating the aerosol-forming substrate to generate aerosol. This effect is especially pronounced if the insulating element extends substantially over the entire length of the combustible heat source. Such insulating elements are also capable of suppressing sustained combustion of a combustible heat source and thus shortening the burning time of a combustible heat source.

It would be desirable to provide an aerosol generating article that has a reduced surface temperature near the heat source and an acceptable appearance and can be assembled in a simple and reliable manner. It would also be desirable to provide an aerosol generating article that generates an acceptable aerosol both during the first puffs and during subsequent puffs.

According to a first aspect of the present invention, there is provided an aerosol generating article comprising an aerosol forming substrate; combustible heat source; and at least one layer of ceramic paper surrounding at least a portion of the length of the combustible heat source. The specified product additionally contains one or more paths of air flow through which it is possible to draw in air by the user through the aerosol generating product; and one or more non-combustible, substantially airtight baffles between the combustible heat source and the aerosol-forming substrate. Said one or more non-combustible, substantially airtight baffles between the combustible heat source and the aerosol forming substrate isolate the combustible heat source from said one or more air flow paths such that, in use, air is drawn through the aerosol generating article along said one or more air paths. flow, does not come into direct contact with a combustible heat source.

In use, a combustible heat source may be ignited by an external heat source such as a lighter and may result in combustion. The combustible heat source has the ability to heat the aerosol-forming substrate so that volatiles from the aerosol-forming substrate evaporate. When a user puffs on the aerosol-generating article, it is possible to draw air into the aerosol-generating article along the specified one or more air flow paths and mix with the vapor released from the heated aerosol-forming substrate to form an aerosol. The specified aerosol is capable of being drawn from the aerosol generating article and delivered to the user for inhalation by the user.

The specified at least one layer of ceramic paper, surrounding at least part of the length of the combustible heat source, allows you to isolate the specified combustible heat source. This makes it possible to lower the surface temperature of the aerosol-generating article at the location of the combustible heat source. Said at least one layer of ceramic paper is also capable of allowing sufficient air to pass through the layer so as to enable a combustible heat source to burn substantially unhindered.

In the context of this document, the term "paper" is used to describe a thin mat or sheet of fibers. Typically, the paper described herein is made from a suspension of fibers compressed into a thin sheet or mat. The paper according to the present invention may contain woven fibers. Typically, however, the paper of the present invention contains nonwoven fibers. The fibers of the paper according to the present invention can be interlaced in an arbitrary manner. The paper described in this document is generally thin. In other words, the thickness or height of said mat or sheet of fibers is substantially less than other dimensions of said mat or sheet, such as the length and width of said mat or sheet. In general, the paper described in this document is flexible. In other words, the paper described herein can be bent or shaped to wrap around the circumferential surface of a combustible heat source so that said paper surrounds at least a portion of the combustible heat source.

In the context of this document, the term "ceramic paper" is used to describe paper containing ceramic material. In other words, the term "ceramic paper" is used to describe a thin mat or sheet of fibrous material containing a ceramic material. In the context of this document, the terms "ceramic paper" and "ceramic fiber paper" are used interchangeably.

The ceramic paper of the present invention may be a fibrous material containing fibers of a ceramic material. Ceramic paper may contain woven ceramic fibers. Ceramic paper may contain non-woven fibers of ceramic material. Ceramic paper may contain a fiber ceramic material containing at least one of the following: ceramic fiber wadding, ceramic fiber felt and ceramic fiber wool. In some embodiments, the ceramic paper may contain only ceramic fibers. In other words, in some embodiments, the ceramic paper may be free of non-ceramic fibers.

Ceramic paper may contain other types of ceramic materials, including particulate ceramic material. Ceramic paper may contain more than one type of ceramic material, such as fibrous ceramic material and particulate ceramic material.

The ceramic material can contain any suitable ceramic material. The ceramic material may contain a crystalline ceramic material. The ceramic material may comprise a semi-crystalline ceramic material. The ceramic material may comprise a non-crystalline ceramic material. The ceramic material can be amorphous. The ceramic material can be semi-crystalline. The ceramic material can be crystalline.

In the context of this document, the term "crystalline material" includes glasses. In the context of this document, the term "glass" is used to describe materials that glass at the glass transition temperature. Typically, the term "glass" is used herein to describe non-crystalline or amorphous solid materials. However, the term "glass" also includes materials containing crystalline components and non-crystalline components. Glass materials containing both crystalline and non-crystalline components may be referred to as "glass ceramic" materials.

The properties of glass materials according to the present invention can be determined by the glass forming method. In the context of this document, the term "glass" includes glasses formed by any suitable method. Suitable methods for forming glasses include: melt quenching; physical vapor deposition; solid phase reactions, including thermochemical and mechanochemical reactions; liquid phase reactions such as the sol-gel method; irradiation of crystalline solids, such as radiation amorphization; and pressure amorphization (i.e. high pressure molding).

In some embodiments, the ceramic material may comprise glass. The ceramic material can be glass. The glass can be a glass-ceramic material. Ceramic paper can contain glass fibers. Ceramic paper may contain glass ceramic fibers.

In some embodiments, the ceramic material may be glass-free. In other words, the ceramic material can contain any ceramic materials other than glass. The ceramic material may not be glass material. The ceramic material may not contain glass fibers. In these embodiments, the ceramic material typically comprises crystalline ceramic materials.

The ceramic material may contain at least one of the following: oxide, carbide, boride, nitride, and silicide. For example, the ceramic material may contain a metal oxide. Ceramic paper may contain at least one of the following: silicon dioxide (SiO ₂ ), calcium oxide (CaO), magnesium oxide (MgO), aluminum oxide (Al ₂ O ₃ ) and zirconia (ZrO ₂ ), all of the above being considered like ceramic materials. For example, the ceramic paper may contain at least one of the following: alkaline earth silicate wool, aluminosilicate wool, and polycrystalline wool. Ceramic paper may contain at least one of the following: iron oxide (Fe ₂ O ₃ ), potassium oxide (K ₂ O) and sodium oxide (Na ₂ O), all of the above being considered as ceramic materials.

Ceramic paper contains any suitable amount of fiber material. Ceramic paper may contain at least about 40 percent by weight of ceramic material; at least about 50 percent by weight of the ceramic material; or at least about 60 percent by weight of the ceramic material. Ceramic paper may contain approximately 100 percent by weight of ceramic material; less than about 100 percent by weight of the ceramic material; less than about 90 percent by weight of the ceramic material; or less than about 80 percent by weight of the ceramic material. For example, ceramic paper can contain from about 50 percent by weight of ceramic material to about 100 percent by weight of ceramic material.

Ceramic paper may contain non-fibrous material. Non-fiber material may contain water.

Ceramic paper may contain non-ceramic material. Non-ceramic material may contain polymeric material. Non-ceramic material may contain organic material. Non-ceramic material may contain inorganic material. The non-ceramic material may contain at least one bonding material for bonding the ceramic material. The non-ceramic material can be any suitable binder material. The binder material may contain one or more organic binders such as bitumens, animal and vegetable adhesives, and polymers. The binder may contain one or more inorganic binders such as lime, cement, gypsum, and water glass. In case the binder contains one or more polymers, these polymers may contain: acrylic resin, phenolic resin, polyester, epoxy resin, polyether, polyvinyl alcohol, styrene-based substance, polycarboxyl ether and polyurethane. The binder may contain carboxymethyl cellulose and / or bentonite. The binder can be an acrylic binder. The non-ceramic material may contain one or more materials for strengthening the ceramic paper. For example, the non-ceramic material may contain polymer fibers such as polyamide and polyimide.

The ceramic paper can be further strengthened with additional means such as a particulate hardener. For example, ceramic paper can be hardened with carbon black particles. Ceramic paper may further contain any suitable components, including but not limited to titanium dioxide, aluminum trihydrate, and pigments that may contain iron and manganese.

Ceramic paper can contain any suitable amount of non-ceramic material. In some embodiments, the ceramic paper may only contain ceramic material. In other words, in some embodiments, the ceramic paper may not contain any non-ceramic materials. Ceramic paper may contain approximately 0 percent by weight of non-ceramic material. Ceramic paper can contain from 0 percent by weight of non-ceramic material to 25 percent by weight of non-ceramic material. Ceramic paper may contain: at least about 0.5 percent by weight of non-ceramic material; at least about 2 percent by weight of non-ceramic material; at least about 10 percent by weight of a non-ceramic material; or at least about 20 percent by weight of a non-ceramic material. Ceramic paper may contain less than about 40 percent by weight of non-ceramic material; less than about 30 percent by weight of non-ceramic material; or less than about 15 percent by weight of a non-ceramic material.

In some embodiments, implementation in which at least one layer of ceramic paper contains 100 percent by weight of ceramic material, this ceramic paper does not contain any additional materials, such as binders or reinforcing materials. By using ceramic paper without any additional materials, there is the advantage of being able to reduce the formation of undesirable compounds when the ceramic material is heated while the combustible heat source is burning, which can affect the user's experience.

In some embodiments, the ceramic paper may contain bio-soluble fibers. In the context of this document, the term "biologically soluble" is used to describe a material that is soluble in a biological system, such as a biological system in a human body. The biological solubility of a material in a particular biological system can differ significantly from the solubility of the specified material in water. In the context of this document, a substance can be considered as biologically soluble if at least 0.1 g of this substance is dissolved in 100 ml of a solvent of the biological system. Likewise, a substance can be considered biologically insoluble if less than 0.1 g of the substance is dissolved in 100 ml of the biological system solvent. Typically, the bio-soluble fibers of the present invention are soluble in the respiratory system of the wearer upon inhalation of the fibers. In other words, the bio-soluble fibers of the present invention typically dissolve in the wearer's respiratory system when the fibers are inhaled. The biologically soluble fiber of the present invention may be soluble in the human alveolar environment.

The biologically soluble material can be any biologically soluble material. Suitable bio-soluble materials include alkaline earth silicate wool and wool with high alumina and low silica content.

In some embodiments, the ceramic paper may contain about 100 percent by weight alkaline earth metal silicate wool.

In some embodiments, the ceramic paper may comprise: from about 50 percent by weight alkaline earth silicate wool to about 100 percent by weight alkaline earth silicate wool; from about 0 percent by weight of a binder, such as an acrylic binder, to about 15 percent by weight of a binder; and less than about 10 percent by weight of an inert inorganic material.

In some embodiments, implementation of the present invention, ceramic paper may contain from about 60 percent by weight of silicon dioxide to about 70 percent by weight of silicon dioxide; from about 15 percent by weight of calcium oxide to about 35 percent by weight of calcium oxide; and from about 4 percent by weight of magnesium oxide to about 20 percent by weight of magnesium oxide.

In some embodiments, implementation of the present invention, ceramic paper may contain: less than about 40 percent by weight of alumina; less than about 10 percent by weight of organic material; and less than about 1 percent by weight moisture.

The above compositions refer to the percentage by weight of the various components after the ceramic paper is burned.

Examples of commercially available suitable ceramic papers containing bio-soluble ceramic fibers include: Superwool® Fiber Paper, Superwool® Fiber Flex Wrap, Superwool® HT Fiber, Superwool® Plus Fiber, and Superwool® Plus 332-E; all of the above are marketed by Morgan Advanced Materials, plc. Other suitable ceramic papers include refractory ceramic fiber ceramic papers marketed by Ningbo Firewheel Thermal Insulation & Sealing Co., Ltd. Non-binder ceramic papers such as Rescor 300 BL from Final Advanced Materials, or non-binder bio-soluble fiber papers from DL-Thermal may also be suitable.

Ceramic paper can have poor thermal conductivity. In other words, ceramic paper can be a good heat insulator. For example, ceramic paper can have a thermal conductivity of about 0.5 to 2 W / mK at a temperature of about 23 ° C. In particular, such low thermal conductivity is observed when the ceramic paper contains a woven or non-woven fiber ceramic material. This may be due to the relatively open, highly porous structure of the ceramic paper containing the fiber ceramic material, resulting in reduced heat transfer due to conduction.

Ceramic paper can be highly breathable. This may be due to the relatively open, highly porous structure. Said at least one layer of ceramic paper may be sufficiently breathable to allow the combustible heat source to burn substantially unhindered. For example, said at least one layer of ceramic paper may have an air permeability of greater than about 4000 (cm ³ / (min * cm ² ).

The specified at least one layer of ceramic paper surrounds at least part of the length of the combustible heat source. Said at least one layer of ceramic paper according to the present invention can surround the combustible heat source over substantially its entire length. This allows the aerosol generating article to take advantage of the insulating properties of the ceramic paper, to lower the surface temperature near the heat source during use, and to take advantage of the breathability of the ceramic paper so that sufficient air can flow to the combustible heat source. ignition and substantially unimpeded combustion of said combustible heat source.

Said at least one layer of ceramic paper may be insulated from said one or more air flow paths so that, in use, air drawn through the aerosol generating article along said one or more air flow paths does not come into direct contact with said at least at least one layer of ceramic paper.

In some embodiments, the implementation of the specified at least one layer of ceramic paper may be spaced from the specified one or more paths of air flow such that air drawn through the aerosol generating article does not come into direct contact with the specified at least one layer of ceramic paper ...

In some embodiments, one or more portions of said at least one layer of ceramic paper may be covered, coated, or encapsulated in a material substantially impermeable to fibers and particles. Said one or more portions of said at least one layer of ceramic paper, which are covered, coated or encapsulated in a material substantially impermeable to fibers and particles, may be located near air drawn through the aerosol generating article along said one or more air flow paths ... Said closure, coating or encapsulation makes it possible to isolate air drawn in through the aerosol generating article along said one or more air flow paths from fibers and particles of said at least one layer of ceramic paper.

In some embodiments, said one or more portions of said at least one layer of ceramic paper may be coated with a paper layer to isolate said at least one layer of ceramic paper from said one or more airflow paths. The specified layer of paper can be provided on the inner surface of the specified at least one layer of ceramic paper and / or on the outer surface of the specified at least one layer of ceramic paper. The specified layer of paper can be provided both on the inner and on the outer surface of the specified at least one layer of ceramic paper. The specified paper layer may contain laminated paper. The specified layer of paper can be laminated together with the specified at least one layer of ceramic paper. The specified layer of paper can be provided only on that part of the specified at least one layer of ceramic paper, which is adjacent to the specified paths of air flow.

The specified at least one layer of ceramic paper may be substantially fire resistant. In the context of this document, the term "flame retardant" refers to a material that remains substantially intact during ignition and combustion of a combustible heat source. The presence of said at least one layer of fire-resistant ceramic paper surrounding at least a portion of the length of the combustible heat source provides the advantage of being able to prevent the emission of flame or smoke from said layer. Thus, it is possible to substantially prevent or reduce the emission of undesirable substances or odors emitted from said layer during combustion of a combustible heat source.

Ceramic paper may have preferred mechanical properties. For example, ceramic paper can be flexible and machinable due to the reinforcing action of the ceramic material, in particular ceramic fibers, if any. The ceramic paper may be machinable to help form a layer of ceramic paper surrounding at least a portion of the length of the heat source.

In the context of this document, the term "layer" is used to describe a body of material generally corresponding to the shape of a combustible heat source. The specified at least one layer of ceramic paper can be any suitable type of layer, made with the possibility of surrounding the heat source. Suitable types of layers include, but are not limited to, wrappers and covers. In the context of this document, the term "coating" is used to describe a layer of material that covers the heat source and is adhered to it.

The specified at least one layer of ceramic paper may be in direct contact with a combustible heat source. Said at least one layer of ceramic paper can be spaced from the combustible heat source.

The specified at least one layer of ceramic paper surrounds at least part of the length of the combustible heat source. For example, said at least one layer of ceramic paper may surround approximately half the length of the combustible heat source. The specified at least one layer of ceramic paper can surround more than half the length of the combustible heat source. The at least one layer of ceramic paper may surround from about 60 percent to about 100 percent of the length of the combustible heat source. The at least one layer of ceramic paper may surround at least about 70 percent of the length of the combustible heat source. The specified at least one layer of ceramic paper can surround at least about 80 percent of the length of the combustible heat source. The at least one layer of ceramic paper may surround at least about 90 percent of the length of the combustible heat source. Said at least one layer of ceramic paper can surround the combustible heat source substantially along its entire length.

The specified at least one layer of ceramic paper can surround the combustible heat source along its entire length. In the context of this document, the term "length" is used to describe the size of a component or portion of an aerosol generating article in the longitudinal direction of that aerosol generating article.

Said at least one layer of ceramic paper may surround approximately half the length of the aerosol-forming substrate. Said at least one layer of ceramic paper surrounding the aerosol-forming substrate provides the advantage of being able to lower the surface temperature of the aerosol-generating article on the aerosol-forming substrate.

Said at least one layer of ceramic paper may surround a combustible heat source at the downstream end of said combustible heat source. This provides the advantage of being able to lower the surface temperature of the aerosol-generating article at the portion of the combustible heat source that is closest to the user during normal use of the aerosol-generating article.

Said at least one layer of ceramic paper may surround a combustible heat source at the upstream end of this combustible heat source.

Said at least one layer of ceramic paper can surround the combustible heat source at the upstream end and at the downstream end.

Uncovered parts of a combustible heat source may be referred to herein as "exposed" parts. Said at least one layer of ceramic paper according to the present invention may be provided to cover or surround "exposed" or uncoated parts of the combustible heat source.

In some embodiments, a portion of the combustible heat source may be surrounded by at least one additional layer at the upstream end. The specified at least one additional layer may be a layer of cigarette paper. In these embodiments, the upstream portion of the combustible heat source is a bare portion. In other words, the part of the combustible heat source located earlier in the course of the flow is not covered by the specified at least one additional layer. In these embodiments, the implementation of the specified at least one layer of ceramic paper may be located upstream of the part of the combustible heat source. Said at least one layer of ceramic paper may surround a combustible heat source in the range from the upstream end of the at least one additional layer surrounding the upstream part of the combustible heat source to the downstream end of the combustible source heat, with adjoining to him or his environment. Thus, in these embodiments, the combustible heat source can be surrounded substantially along its entire length by a combination of said at least one additional layer at the downstream end and said at least one layer of ceramic paper at the upstream end. end. In some embodiments, the implementation of the specified at least one layer of ceramic paper and the specified at least one additional layer may be superimposed on each other along the entire length of the combustible heat source.

The combustible heat source, aerosol-forming substrate, and said at least one layer of ceramic paper may be configured to substantially prevent or reduce the likelihood that the temperature of the aerosol-forming substrate will exceed about 375 ° C during combustion of said combustible heat source. For example, a combustible heat source, an aerosol-forming substrate, and said at least one layer of ceramic paper may be shaped, sized, and positioned to substantially prevent or reduce the likelihood that the temperature of the aerosol-forming substrate will exceed about 375 ° C during combustion. the specified combustible heat source. In this way it is possible to maintain the integrity of the aerosol-forming substrate. For example, if the aerosol-forming substrate contains one or more aerosol-forming agents, the aerosol-forming agents may be pyrolyzed at temperatures above about 375 ° C. At even higher temperatures and if, for example, tobacco is present in the aerosol-forming substrate, the tobacco can ignite.

The combustible heat source, aerosol-forming substrate and said at least one layer of ceramic paper may be configured such that, during combustion of the combustible heat source, the temperature of the aerosol-forming substrate at a distance of 2 mm from the nearest end of said aerosol-forming substrate is at least about 100 ° C for a period of approximately 6 minutes.

The specified at least one layer of ceramic paper can be of any suitable thickness. In general, said at least one layer of ceramic paper is a thin layer. The thickness of the specified at least one layer of ceramic paper may be at least about 0.25 millimeter or at least 0.5 millimeter. The thickness of the specified at least one layer of ceramic paper may be less than about 10 millimeters or less than about 5 millimeters. Said at least one layer of ceramic paper can have a thickness of from about 0.25 millimeters to about 10 millimeters, or from about 0.5 millimeters to about 5 millimeters.

The specified at least one layer of ceramic paper may further comprise one or more air inlets, such as one or more perforations. Said one or more air inlets provide the ability to further increase the air permeability of said at least one layer of ceramic paper.

An aerosol generating article according to the present invention comprises an aerosol forming substrate. In the context of this document, the term "aerosol-forming substrate" is used to describe a substrate capable of releasing volatile compounds that are capable of forming an aerosol when heated. Aerosols generated from aerosol-forming substrates of aerosol-generating articles of the present invention may be visible or invisible and may contain vapors (for example, fine particles of gaseous substances, which are usually liquid or solid at room temperature), as well as gases and droplets liquid condensed vapors.

The aerosol-forming substrate can be solid. The aerosol-forming substrate can be solid at room temperature.

Preferably, the aerosol-forming substrate contains at least one aerosol-forming agent and at least one material capable of releasing volatile compounds when heated.

Said at least one aerosolizing agent may be any suitable known compound or mixture of compounds that, in use, promote the formation of a dense and stable aerosol and are substantially resistant to thermal decomposition at the operating temperature of the aerosol generating article. Suitable aerosol forming agents are well known in the art and include, for example, polyhydric alcohols, polyhydric alcohol esters such as glycerol mono-, di- or triacetate, and aliphatic mono-, di- or polycarboxylic acid esters such as dimethyl dodecanedioate and dimethyl tetradecanedioate. Examples of aerosol generating agents for use in aerosol generating articles of the present invention are polyhydric alcohols or mixtures thereof such as triethylene glycol, 1,3-butanediol, and glycerin.

The material capable of releasing volatile compounds when heated may be a portion of a plant material, for example a portion of a homogenized plant material. For example, the aerosol-forming substrate can comprise one or more plant derived materials, including, but not limited to: tobacco; tea, such as green tea; peppermint; laurel; eucalyptus; basilica; sage; vervain; and tarragon. The plant material may contain additives, including, but not limited to, humectants, fragrances, binders, and mixtures thereof. The plant material may be composed of substantially tobacco material, optionally homogenized tobacco material.

Aerosol-generating articles of the present invention may contain aerosol-generating substrates containing nicotine. For example, aerosol-generating articles of the present invention comprise aerosol-generating substrates containing tobacco.

The aerosol-forming substrate may be surrounded by the filter filament.

Aerosol generating articles of the present invention comprise a combustible heat source configured to heat the aerosol forming substrate and isolated from said one or more airflow paths.

A combustible heat source may contain a body of combustible material. The combustible heat source body may have a substantially constant diameter. The body of a combustible heat source can have a constant diameter along its entire length. This provides the advantage of being able to simplify the processes used in the manufacture of a combustible heat source and aerosol generating article. In some embodiments, the body of combustible material may be a substantially circular cylindrical body having a substantially constant diameter throughout its length.

The combustible heat source can be a carbon heat source. In the context of this document, the term "carbon" is used to describe a combustible heat source containing carbon. Preferably, the carbon content of the carbon combustible heat sources for use in aerosol generating articles of the present invention is at least about 35 percent, more preferably at least about 40 percent, most preferably at least about 45 percent, based on dry fuel weight. heat source.

The combustible heat source of the present invention is a carbon-based combustible heat source. In the context of this document, the term "carbon-based heat source" is used to describe a heat source containing mainly carbon.

Carbon-based combustible heat sources for use in aerosol generating articles of the present invention may have a carbon content of at least about 50 percent, preferably at least about 60 percent, more preferably at least about 70 percent, most preferably at least about 80 percent, based on the dry weight of the carbon-based combustible heat source.

The combustible heat source of the present invention is isolated from said one or more air flow paths passing through the aerosol generating article. In the context of this document, the term "airflow path" is used to describe the path by which air is allowed to be drawn through the aerosol generating article for inhalation by the user. In the context of this document, the terms "upstream" and "downstream" are used to describe the relative directions and locations of the components of the aerosol generating article with respect to the direction of air flows through the one or more air flow paths when the user puffs the aerosol generating article.

By isolating the combustible heat source from said one or more air flow paths of the aerosol generating article, it is possible to substantially prevent or reduce the activation of combustion of the combustible heat source during puffs by the user. This makes it possible to substantially prevent or reduce temperature jumps in the aerosol-forming substrate during puffs by the user. This makes it possible to substantially prevent or attenuate combustion or pyrolysis of the aerosol-forming substrate in high puff conditions. This makes it possible to substantially prevent or reduce variations in the composition of the aerosol generated by the aerosol-generating article, depending on the puff behavior of the user.

By isolating the combustible heat source from said one or more air flow paths, it is also possible to substantially prevent or reduce the ingress of combustion and decomposition products and other substances generated during the ignition and combustion of the combustible heat source into the air drawn through the aerosol generating article according to specified one or more airflow paths.

An insulated combustible heat source according to the present invention may comprise a solid heat source. In the context of this document, the term "solid" is used to describe a combustible heat source in which air drawn in through the aerosol generating article for inhalation by the user does not pass through the airflow channel in the specified combustible heat source. Thus, heat transfer between the continuous combustible heat source and the aerosol-forming substrate is mainly due to conductive heat transfer.

By eliminating airflow channels through the combustible heat source, convective heat transfer between the combustible heat source and the aerosol-forming substrate is reduced or minimized. By reducing convective heat transfer between the combustible heat source and the aerosol-forming substrate, it is possible to substantially prevent or reduce temperature jumps in the aerosol-forming substrate during puffs by the user. This makes it possible to substantially prevent or attenuate combustion or pyrolysis of the aerosol-forming substrate in high puff conditions. This makes it possible to substantially prevent or reduce changes in the composition of the aerosol generated by the aerosol-generating article, depending on the puff behavior of the user. This also makes it possible to substantially prevent or reduce the entry of combustion and decomposition products and other substances generated during the ignition and combustion of the combustible heat source into the air drawn through the aerosol generating article along the one or more air flow paths.

The insulated combustible heat source of the present invention may comprise a non-continuous heat source. In the context of this document, the term "discontinuous" is used to describe a heat source in which air drawn in through an aerosol-generating article for inhalation by a user passes through one or more airflow channels in a specified combustible heat source. This makes it possible for heat transfer between the discontinuous combustible heat source and the aerosol-forming substrate to take place both by conductive heat transfer and by convective heat transfer through said one or more air flow channels.

In the context of this document, the term "airflow duct" is used to describe a duct that extends along the entire length of a combustible heat source and through which air can be drawn downstream for inhalation by a user. Thus, the aerosol generating article of the present invention may be free of one or more air flow channels.

Said one or more non-combustible, substantially airtight baffles between the combustible heat source and the aerosol-forming substrate may comprise a first baffle that is adjacent to the proximal end of the combustible heat source and / or the distal end of the aerosol-forming substrate. The first baffle provides the ability to assist in isolating the combustible heat source from said one or more airflow paths in the aerosol generating article. The first baffle allows the maximum temperature to be exposed to the aerosol-forming substrate during ignition or combustion of the combustible heat source, and the ability to substantially prevent or reduce thermal decomposition or combustion of the aerosol-forming substrate during use of the aerosol-generating article.

In the context of this document, the term "non-combustible" is used to describe a material that is substantially non-combustible at temperatures reached by a combustible heat source during combustion or ignition.

In the context of this document, the term "airtight" is used to describe a material that substantially prevents or reduces the passage of air through it.

The first baffle may abut the proximal end of the combustible heat source and / or the distal end of the aerosol-forming substrate. The first baffle may be adhered or otherwise attached to the proximal end of the combustible heat source and / or to the distal end of the aerosol-forming substrate.

The first baffle may include a first barrier coating provided at the proximal end of the combustible heat source. In such embodiments, the first baffle may include a first barrier coating provided on at least substantially the entire proximal end of the combustible heat source. The first baffle may include a first barrier coating provided at the entire proximal end of the combustible heat source. The first barrier coating can be formed and applied to the proximal end of the combustible heat source in any suitable manner, such as those described in WO-A1-2013120855.

Depending on the required characteristics and operating parameters of the aerosol generating article, the first baffle may have low thermal conductivity or high thermal conductivity. In some embodiments, the first baffle may have a thermal conductivity of from about 0.1 W / mK to about 200 W / mK.

The thickness of the first baffle can be appropriately adjusted to provide good aerosol generation performance. In some embodiments, the first baffle may be from about 10 microns to about 500 microns thick.

The first baffle can be made of one or more suitable materials that are substantially thermally stable and non-combustible at temperatures reached by a combustible heat source during ignition and combustion. Suitable materials are known in the art and include, but are not limited to, clays (such as bentonite and kaolinite), glasses, minerals, ceramics, resins, metals, and combinations thereof.

Materials from which the first baffle can be formed include clays and glasses. Additional materials from which the first baffle may be formed include copper, aluminum, stainless steel, alloys, alumina (Al ₂ O ₃ ), resins, and mineral adhesives.

In the event that the first baffle contains a metal or alloy such as copper, aluminum and stainless steel, the first barrier coating provides the advantage of being able to act as a thermal bond between the combustible heat source and the aerosol forming substrate. This makes it possible to improve the conductive heat transfer from the combustible heat source to the aerosol-forming substrate.

The aerosol generating article may further comprise one or more air inlets located downstream of the proximal end of the combustible heat source. In some embodiments, said one or more air inlets are located between the proximal end of the combustible heat source and the proximal end of the aerosol generating article. Said one or more air inlets may be positioned to allow air to be drawn into said one or more air flow paths of the aerosol generating article through said one or more air inlets without air being drawn through a combustible heat source. In this way, it is possible to substantially prevent or mitigate temperature surges in the aerosol-forming substrate during puffs by the user.

The one or more air inlets may include any suitable air inlets through which air can be drawn into the interior of the aerosol generating article. For example, suitable air inlets include holes, slots, slots, or other openings. The number, shape, size, and location of the air inlets can be appropriately adjusted to achieve good aerosol generation performance.

Said one or more air inlets may be located in the aerosol-forming substrate. Said one or more air inlets may be located between the distal end of the aerosol-forming substrate and the proximal end of the aerosol-forming substrate. In the event that said one or more air inlets are located in the aerosol-forming substrate and said aerosol-forming substrate comprises a filter filament, the filter filament may be provided with one or more openings to allow air to enter the aerosol-forming substrate. These one or more openings may be slots, slots, or any other suitable openings through which air can be drawn into the interior of the aerosol-forming substrate. The number, shape, size and location of these openings can be appropriately adjusted to achieve good aerosol generation performance.

The combustible heat source may contain one or more airflow channels. In other words, the combustible heat source can be a discontinuous heat source. Said one or more air flow channels can extend along the entire length of the combustible heat source. Said one or more air flow paths may form portions of said one or more air flow paths in an aerosol generating article.

In case the combustible heat source contains one or more air flow channels in the aerosol generating article, said one or more non-combustible, substantially airtight baffles between the combustible heat source and the aerosol-forming substrate may further comprise a second baffle between the combustible heat source and said one or more airflow channels in a combustible heat source.

The second baffle is capable of helping to isolate the combustible heat source from said one or more air flow paths in the aerosol generating article. The second baffle allows the maximum temperature to be exposed to the aerosol-forming substrate during ignition or combustion of the combustible heat source and thus helps to prevent or reduce thermal decomposition or combustion of the aerosol-forming substrate during use of the aerosol-generating article.

The second baffle can be glued or otherwise attached to the combustible heat source.

The second baffle may comprise a second barrier coating provided on the inner surface of said one or more airflow channels. The second baffle may comprise a second barrier coating provided on at least substantially the entire inner surface of said one or more air flow channels. The second baffle may comprise a second barrier coating provided over the entire inner surface of said one or more air flow channels.

The second barrier coating can be provided by introducing the liner into said one or more airflow channels. For example, in the event that said one or more airflow channels comprise one or more airflow channels passing through an interior region of a combustible heat source, a non-combustible, substantially airtight hollow tube may be inserted into each of said one or more airflow channels.

The second baffle provides the advantage of being able to substantially prevent or reduce the entry of combustion and decomposition products generated during the ignition and combustion of a combustible heat source in smoking articles according to the present invention into air drawn downstream of said one or more air ducts. flow.

Depending on the required characteristics and operating parameters of the aerosol generating article, the second baffle may have low thermal conductivity or high thermal conductivity. The second baffle may have low thermal conductivity.

The thickness of the second baffle can be appropriately adjusted to achieve good aerosol generation performance. In some embodiments, the second baffle may be from about 30 microns to about 200 microns thick. In an embodiment, the second baffle has a thickness of about 30 microns to about 100 microns.

The second baffle can be made of one or more suitable materials that are substantially thermally stable and non-combustible at temperatures reached by the combustible heat source during ignition and combustion. Suitable materials are known in the art and include, but are not limited to, for example: clays; metal oxides such as iron oxide, aluminum oxide, titanium oxide, silicon oxide, aluminosilicate, zirconium dioxide and cerium oxide; zeolites; zirconium phosphate; and other ceramic materials or combinations thereof.

The materials from which the second baffle can be formed include clays, glasses, aluminum, iron oxide, and combinations thereof. If necessary, catalytic ingredients such as ingredients that promote the oxidation of carbon monoxide to carbon dioxide can be included in the second baffle. Suitable catalytic ingredients include, but are not limited to, for example, platinum, palladium, transition metals, and their oxides.

Where aerosol-generating articles of the present invention comprise a first baffle between the downstream end of the combustible heat source and the upstream end of the aerosol-forming substrate, and a second baffle between the combustible heat source and one or more air flow channels through the combustible source heat, said second baffle may be formed from the same material or materials as the first baffle, or from a different material or materials.

In case the second baffle comprises a second barrier coating provided on the inner surface of said one or more airflow channels, said second barrier coating may be applied to the inner surface of said one or more airflow channels by any suitable method, such as the methods described in US-A-5,040,551 and WO-A1-2013120855.

The aerosol generating article may further comprise one or more additional layers surrounding at least the proximal portion of the combustible heat source and the distal portion of the aerosol forming substrate. Said one or more additional layers may comprise a heat transfer member for transferring heat from a combustible heat source to an aerosol-forming substrate and / or a layer of cigarette paper.

The heat transfer element can only surround the distal part of the aerosol-forming substrate. The thermally conductive element can surround substantially the entire length of the aerosol-forming substrate. The thermally conductive material can be in direct contact with a combustible heat source and / or an aerosol-forming substrate. The thermally conductive material can be in direct contact with both a combustible heat source and an aerosol-forming substrate.

The heat transfer element can provide thermal communication between the combustible heat source and the aerosol-forming substrate. The heat transfer element can be substantially fire resistant.

Suitable thermally conductive elements may include metal foil wrappers or metal alloy foil wrappers. Metallic foil wrappers can include: aluminum foil wrappers, steel foil wrappers, iron foil wrappers, and copper foil wrappers. The heat transfer element may comprise an aluminum tube.

The proximal part of the combustible heat source, surrounded by the heat transfer element, can be from about 2 millimeters to about 8 millimeters in length, or from about 3 millimeters to about 5 millimeters in length.

The distal part of the combustible heat source, not surrounded by the heat transfer element, can be from about 4 millimeters to about 15 millimeters in length, or from 4 millimeters to about 8 millimeters in length.

The layer of cigarette paper may surround at least the proximal portion of the combustible heat source, the aerosol-forming substrate along its entire length, and any other components of the aerosol-generating article located in the vicinity of the aerosol-forming substrate. The layer of cigarette paper may surround the combustible heat source over substantially its entire length. In the event that a layer of cigarette paper surrounds the combustible heat source substantially along its entire length, this layer of cigarette paper may be provided with ventilation means, such as perforations, slots or slots, on the combustible heat source in order to allow air to pass through the specified a layer of cigarette paper to the specified combustible heat source. The number, shape, size and location of these openings can be appropriately adjusted to achieve good aerosol generation performance. The layer of cigarette paper may be wrapped tightly around the combustible heat source and aerosol-generating substrate such that said layer of cigarette paper grips and holds the combustible heat source and aerosol-forming substrate during assembly of the aerosol generating article.

Said at least one layer of ceramic paper may be a radially outer layer. In case the aerosol generating article comprises one or more additional layers, the radially outer layer of ceramic paper may overlap with at least a portion of said one or more additional layers. In other words, said one or more additional layers may be located between the combustible heat source and the specified at least one layer of ceramic paper. For example, in the case where the aerosol generating article comprises an additional layer containing a thermally conductive element, this thermally conductive element may be a radially inner layer, and said at least one ceramic paper layer may be a radially outer layer surrounding at least least part of the specified heat-conducting element.

In the context of this document, the terms "radially outer" and "radially inner" are used to refer to the relative distances between the components of the aerosol generating article and the longitudinal axis of the aerosol generating article. In the context of this document, the term "radial" is used to describe a direction perpendicular to the longitudinal axis of the aerosol generating article that extends in the direction between the proximal end and the distal end of the aerosol generating article.

These one or more additional layers may be radially outer layers. Said one or more additional layers may overlap with at least a portion of said at least one layer of ceramic paper.

The specified at least one layer of ceramic paper can be attached or attached to one or more other components or parts of the aerosol generating article. The specified at least one layer of ceramic paper can be attached to any suitable component of the aerosol generating article. For example, said at least one layer of ceramic paper may be attached to at least one of the following: a combustible heat source, an aerosol-forming substrate, and said one or more additional layers. Said at least one layer of ceramic paper may be attached to one or more components of the aerosol generating article by any suitable means. The specified at least one layer of ceramic paper can be attached with an adhesive. Suitable adhesives can have high heat resistance such as silicate glue. In the event that said one or more additional layers are radially outer layers, said one or more additional layers may be tightly wrapped around at least a portion of said at least one ceramic paper layer.

In some embodiments, the implementation of the specified at least one layer of ceramic paper may form an integral whole with a combustible heat source. In the context of this document, the term "forms a whole" is used to describe a layer that is in direct contact with a combustible heat source and is attached to the specified combustible heat source without the help of an external adhesive or other intermediate bonding material.

In some embodiments, the implementation of the specified at least one layer of ceramic paper may be formed from a strip of ceramic paper having opposite ends. Said strip of ceramic paper can be wrapped around a combustible heat source so that opposite ends of said strip are superimposed on each other. The superimposed opposite ends of the specified strip can be attached to each other using an adhesive or any other suitable means. Thus, it is possible to fix the specified at least one layer of ceramic paper on a combustible heat source.

In some embodiments, an intermediate layer may be provided between said at least one layer of ceramic paper and at least one of a combustible heat source, an aerosolizing substrate and said one or more additional layers. The intermediate layer can be adjacent to the specified at least one layer of ceramic paper. The intermediate layer can be in contact with the specified at least one layer of ceramic paper. The intermediate layer can be located on the inner side in the radial direction relative to the specified at least one layer of ceramic paper.

The intermediate layer can be an adhesive layer. The adhesive layer can contain any suitable adhesive. Suitable adhesives can have high heat resistance such as silicate glue. An adhesive layer may be positioned between said at least one ceramic paper layer and a combustible heat source, and has the ability to adhere said at least one ceramic paper layer to a combustible heat source. An adhesive layer may be positioned between said at least one ceramic paper layer and said one or more additional layers, and has the ability to adhere said at least one ceramic paper layer to said one or more additional layers. An adhesive layer may be positioned between said at least one ceramic paper layer and an aerosol-forming substrate, and has the ability to adhere said at least one ceramic paper layer to an aerosol-forming substrate.

In some embodiments, the implementation of the specified at least one layer of ceramic paper may be formed from a strip of ceramic paper having opposite ends. The specified strip of ceramic paper can be wrapped around the combustible heat source so that the opposite ends of the strip are adjacent to each other without overlapping. On the side of said strip which faces the combustible heat source, an adhesive layer may be provided at at least opposite ends of said strip. The adhesive layer has the ability to attach a strip of ceramic paper to a combustible heat source at least at opposite ends of said strip.

The aerosol generating article may contain a heat transfer component located between the combustible heat source and the aerosol forming substrate. The heat transfer component can be the above-described first baffle. The aerosol generating article may include a heat transfer component and a first baffle. The thermally conductive component may contain the same material as said thermally conductive element. The aerosol generating article may include a heat transfer component and a heat transfer element. The presence of the heat transfer element and / or the heat transfer component makes it possible to promote conductive heat transfer between the combustible heat source and the aerosol forming substrate.

The aerosol generating article may further comprise any suitable components. For example, an aerosol generating article may comprise at least one of the following: a transfer member; aerosol cooling element; dividing element; and a mouthpiece. These one or more additional components may be located coaxially with the combustible heat source and aerosol-forming substrate. These one or more additional components may be located in the vicinity of the aerosol-forming substrate. These one or more additional components can be located in any suitable order. The aerosol generating article may further comprise: a transfer member adjacent to the proximal end of the aerosol forming substrate; an aerosol cooling element adjacent to the proximal end of the transfer element; a spacer element adjacent to the proximal end of the aerosol cooling element; and a mouthpiece adjacent to the proximal end of the spacer.

In the context of this document, the terms "near" and "far" are used to describe the relative positioning of components or parts of components of aerosol generating articles according to the present invention. The proximal end of the aerosol generating article component is that end of the said component that is closest to the mouth end of the aerosol generating article, and the distal end of the aerosol generating article component is that end of the said component that is farthest from the mouth end of the aerosol generating article. Typically, a combustible heat source is located at the distal end of the aerosol generating article.

According to a second aspect of the present invention, there is provided a method of manufacturing an aerosol generating article according to the first aspect of the present invention. The method includes the steps of: placing a combustible heat source to heat the aerosol-forming substrate; providing one or more air flow paths that allow air to be drawn in through the aerosol generating article for inhalation by a user; isolating the combustible heat source from said one or more air flow paths so that, in use, air drawn through the aerosol generating article along said one or more air flow paths does not come into direct contact with the combustible heat source; and surrounding at least a portion of the length of the combustible heat source with at least one layer of ceramic paper.

In some embodiments, the step of surrounding at least a portion of the length of the combustible heat source with at least one layer of ceramic paper may include: providing a strip of ceramic paper having opposite ends; wrapping said strip around a combustible heat source so that said combustible heat source is surrounded by at least one layer of ceramic paper; overlap the opposite ends of the specified strip; and the superimposed ends are fastened together to secure the at least one layer of ceramic paper to the combustible heat source.

The overlapping ends of the ceramic paper strip may be bonded together using any suitable means. For example, the overlapping ends of a strip of ceramic paper may be bonded together with an adhesive. Suitable adhesives should be highly heat resistant and include silicone adhesive.

In some embodiments, the step of surrounding at least a portion of the length of the combustible heat source with at least one layer of ceramic paper may include: providing a strip of ceramic paper having opposite ends; applying a layer of adhesive to one side of said strip at least at each of said opposite ends; place the specified strip so that the specified layer of adhesive is facing the combustible heat source; wrapping the specified strip around the combustible heat source in such a way that at least part of the length of the combustible heat source is surrounded by at least one layer of ceramic paper; provide the abutment of the opposite ends of the specified strip without overlapping these opposite ends; and attaching said strip to a combustible heat source using said layer of adhesive.

In some embodiments, the implementation of the specified at least one layer of ceramic paper may be laminated with an additional layer, such as a layer of cigarette paper. Said at least one layer of ceramic paper may be laminated with an additional layer prior to applying said at least one layer of ceramic paper to the combustible heat source. A strip of co-laminated paper containing at least one layer of ceramic paper and an additional layer can be wrapped around a combustible heat source in the same way as the strip of ceramic paper. In some embodiments, the co-laminated paper may be positioned such that at least one layer of ceramic paper faces a combustible heat source. In other words, the specified at least one layer of ceramic paper can be located on the radially inner side of the additional layer. In some embodiments, the co-laminated paper may be positioned so that the additional layer faces a combustible heat source.

The present invention will be further described solely by way of example, with reference to the accompanying drawings, in which:

in fig. 1 is a schematic view of a first embodiment of an aerosol generating article according to the present invention, comprising a continuous combustible heat source;

in fig. 2 shows the temperature profile of the aerosol generating article of FIG. 1 in first place;

in fig. 3 shows the temperature profile of the aerosol generating article of FIG. 1 in second place;

in fig. 4 shows the temperature profile of the aerosol generating article of FIG. 1 in third place; and

in fig. 5 is a schematic view of a second embodiment of an aerosol generating article according to the present invention comprising a non-continuous combustible heat source.

FIG. 1 shows a schematic view of an aerosol-generating article 2. The aerosol-generating article 2 comprises a combustible heat source 3. The combustible heat source 3 comprises a substantially circular cylindrical body of carbon material having a length of approximately 10 millimeters. The combustible heat source 3 is a continuous heat source. In other words, the combustible heat source 3 does not contain any air channels passing through it.

The aerosol-generating article 2 further comprises an aerosol-forming substrate 4. The aerosol-forming substrate 4 is located at the proximal end of the combustible heat source 3. The aerosol-forming substrate 4 comprises a substantially circular cylindrical plug of tobacco material 18 surrounded by a filter filler 19.

Between the proximal end of the combustible heat source 3 and the distal end of the aerosol-forming substrate 4 is a non-combustible, substantially airtight first baffle 6. The first baffle 6 comprises an aluminum foil disc. The first baffle 6 also forms a heat transfer element located between the combustible heat source 3 and the aerosol-forming substrate 4 and intended to transfer heat from the proximal end of the combustible heat source 3 to the distal end of the aerosol-forming substrate 4.

The heat transfer element 9 surrounds the proximal portion of the combustible heat source 3 and the distal portion of the aerosol-forming substrate 4. The heat transfer element 9 comprises an aluminum foil tube. The heat-conducting element 9 is in direct contact with the proximal part of the combustible heat source 3 and the phycella 19 of the filter of the aerosol-forming substrate 4.

The aerosol-generating article 2 further comprises various other components located in the vicinity of the aerosol-forming substrate 4, including: a transfer element 11 located at the proximal end of the aerosol-forming substrate 4; an aerosol cooling element 12 disposed at a proximal end of the transfer element 11; a separating member 13 located at the proximal end of the aerosol cooling member 11; and a mouthpiece 10 located at the proximal end of the spacer 13.

The components of the aerosol generating article 2 are wrapped in a layer of cigarette paper 7. The layer 7 of cigarette paper surrounds the heat transfer member 9 but does not extend beyond the distal end of the heat transfer member 9, overlying the distal portion of the combustible heat source 3.

According to the present invention, the aerosol-generating article 2 further comprises a layer of ceramic paper 5. The ceramic paper layer 5 surrounds substantially the entire length of the combustible heat source 3 as well as the distal part of the cigarette paper layer 7, the heat-conducting element 9 and the aerosol-forming substrate 4. In other words the ceramic paper layer 5 is a radially outer layer at the distal end of the aerosol generating article 2.

The ceramic paper layer 5 contains from about 60 percent by weight of silicon dioxide to about 70 percent by weight of silicon dioxide; from about 16 percent by weight of calcium oxide to about 22 percent by weight of calcium oxide; and from about 12 percent by weight of magnesium oxide to about 19 percent by weight of magnesium oxide. The ceramic paper layer 5 also contains alumina and a binder.

In the aerosol-forming substrate 4, a plurality of air inlets 8 are formed to allow ambient air to be drawn into the interior of the aerosol-generating article 2. The air inlets 8 comprise a plurality of perforations through the ceramic paper layer 7 and an underlying phycella layer 19 that surrounds the aerosol-generating substrate 4. Air inlets 8 are located between the distal end and the proximal end of the aerosol-forming substrate 4.

When the user puffs on the mouthpiece 10 of the aerosol generating article 2, it is possible to draw ambient air into the aerosol generating article 2 through the air inlets 8. The air drawn into the interior of the aerosol generating article 2 is allowed to flow in the air flow path in the aerosol generating article 2 from the air inlets 8 through the aerosol forming substrate 4, the transfer element 11, the cooling element 12 and the separating element 13 to the mouthpiece 10 and out mouthpiece 10 to the user for inhalation. The general direction of the air flow through the aerosol generating article 2 is shown by arrows.

In use, the user is able to ignite the combustible heat source 3 by exposing said combustible heat source 3 to an external heat source such as a lighter. The combustible heat source 3 is able to ignite and burn, and it is possible to transfer heat from the combustible heat source 3 to the aerosol-forming substrate 4 by heat transfer through the heat-conducting component 6 and the heat-conducting element 9. The volatile components of the aerosol-forming substrate 4 are allowed to evaporate. The user is able to tighten the mouthpiece 10 of the aerosol generating article 2 by drawing ambient air into the air flow path in the aerosol generating article 2 through the air inlets 8. The vapor from the heated aerosol-forming substrate 4 is able to be entrained in the air drawn in through the aerosol-forming substrate 4 and is able to be drawn in with the air towards the mouthpiece 10. As the steam is drawn in towards the mouthpiece 10, it is possible to cool said vapor to form an aerosol. The specified aerosol can be drawn from the mouthpiece 10 and delivered to the user for inhalation.

It will be appreciated that the substantially airtight first baffle 6 reduces air being drawn through the combustible heat source 3 into the aerosol-forming substrate 4. Thus, the first baffle 6 substantially isolates the airflow path in the aerosol-generating article 2 from the combustible heat source 3.

In this embodiment, the ceramic paper layer 5 extends over a small portion of the distal end of the aerosol-forming substrate 4. Thus, the ceramic paper layer 5 is spaced from the air inlets 8. This gap substantially insulates the ceramic paper layer 5 from the air inlets 8 so that air drawn in through the airflow path in the aerosol generating article 2 does not come into contact with the ceramic paper layer 5.

It will be appreciated that in some embodiments, the ceramic paper layer may be in close proximity to the air inlets. In these embodiments, those portions of the ceramic paper layer that are in close proximity to the air inlets may be coated with a material substantially impermeable to fibers and particles. In this way, it is possible to substantially insulate those portions of the ceramic paper layer that are in close proximity to the air inlets so that air drawn in through the air flow path in the aerosol generating article does not come into contact with the ceramic paper layer.

Experimental data were collected to determine the temperature of combustible heat sources and aerosol-forming substrates in various aerosol-generating articles, similar to aerosol-generating article 2 shown in FIG. 1 during the combustion period of the combustible heat source. Each of the aerosol generating articles tested contained a distinct layer of material surrounding the combustible heat source over substantially its entire length. In particular, experimental data were collected for aerosol generating articles comprising a layer of ceramic paper surrounding a combustible heat source substantially along its entire length, and not containing a layer of material surrounding a combustible heat source substantially along its entire length. FIG. Figures 2-4 show plots of experimental temperature measurements versus time at three different locations on different aerosol generating articles.

FIG. 2 shows the temperature measured at a location 2 millimeters from the distal end of the combustible heat source, which corresponds to location T ₁ shown in FIG. 1. In other words, in FIG. 2 shows the temperature at the far end of a combustible heat source.

FIG. 3 shows the temperature measured at a location 5 millimeters from the distal end of the combustible heat source, which corresponds to location T ₂ shown in FIG. 1. In other words, in FIG. 3 shows the temperature at a location approximately midway along the length of a combustible heat source.

FIG. 4 shows the temperature measured at a location 11 millimeters from the distal end of the combustible heat source, which corresponds to location T ₃ shown in FIG. 1. In other words, in FIG. 4 shows the temperature at the distal end of the aerosol-forming substrate.

All of these temperature profiles were measured with electronic temperature probes that were inserted approximately 2 millimeters deep into the proper components of the aerosol generating articles.

FIG. 2, 3 and 4, the "SMAR" line, labeled 20, shows the temperature profile of an aerosol generating article with a "exposed" combustible heat source. In other words, line 22 "SMAR" shows the temperature profile of the aerosol generating article without a layer of material surrounding the combustible heat source over substantially its entire length.

FIG. 2, 3 and 4, the line “ceramic paper 1” at 21 shows the temperature profile of an aerosol generating article with a ceramic paper layer surrounding a combustible heat source over substantially its entire length, in accordance with the present invention. The ceramic paper surrounding substantially the entire length of the combustible heat source in the Ceramic Paper 1 test was Superwool® Plus Fiber, commercially available from Morgan Advanced Materials, plc.

FIG. 2, 3 and 4, the line “ceramic paper 2” at 22 shows the temperature profile of an aerosol generating article with a ceramic paper layer surrounding a combustible heat source over substantially its entire length, in accordance with the present invention. The ceramic paper surrounding substantially the entire length of the combustible heat source in Ceramic Paper 2 was CFP Ceramic Fiber Paper commercially available from Ningbo Firewheel Thermal Insulation & Sealing Co., Ltd.

FIG. 2, 3 and 4, the line “ceramic paper 2” at 22 shows the temperature profile of an aerosol generating article with a ceramic paper layer surrounding a combustible heat source over substantially its entire length, in accordance with the present invention. The ceramic paper surrounding substantially the entire length of the combustible heat source in Ceramic Paper 2 was CFP Ceramic Fiber Paper commercially available from Ningbo Firewheel Thermal Insulation & Sealing Co., Ltd.

FIG. 2, 3 and 4, the "glass paper" line at 23 shows the temperature profile of an aerosol generating article with a ceramic paper layer surrounding a combustible heat source over substantially its entire length, in accordance with the present invention. The ceramic paper surrounding substantially the entire length of the combustible heat source in the glass paper test was a ceramic paper containing glass fibers.

Desirably, aerosol generating articles having a layer of material surrounding the aerosol generating article substantially along its entire length exhibit temperature profiles substantially similar to or greater than the temperature profile 20 of the aerosol generating article with a bare combustible heat source, without a layer of material surrounding the combustible heat source. essentially along the entire length. If the combustible heat source exhibits a similar or higher temperature than the exposed combustible heat source, then this means that the layer of material surrounding the combustible heat source substantially along its entire length does not substantially attenuate combustion of the combustible heat source.

Surprisingly, as shown in FIG. 2, 3 and 4, the temperature profiles 21, 22, 23 of an aerosol generating article having a ceramic paper layer surrounding a combustible heat source substantially along its entire length were substantially similar to the temperature profile 20 of an aerosol generating article without the ceramic paper layer surrounding the combustible source. heat substantially along the entire length, at all three locations of the aerosol generating article tested, during most of the combustion time of the combustible heat source. Moreover, the temperature profiles 21 and 22 of an aerosol generating article having a ceramic paper layer surrounding a combustible heat source substantially along its entire length substantially exceeded the temperature profile 20 of an aerosol generating article without a ceramic paper layer surrounding the combustible heat source substantially along its entire length. for periods of time during an aerosol generation session.

This surprising result shows that by providing at least one layer of ceramic paper surrounding the combustible heat source substantially its entire length, there is the advantage of substantially not interfering with the combustion of the combustible heat source. In fact, by providing said layer of ceramic paper, it is possible to increase the temperature of the combustible heat source for periods of time during the combustion of said combustible heat source.

Aerosol generating articles of the present invention were also tested by observing the effect of being placed on Whatman paper sheets after ignition of a combustible heat source. For example, aerosol generating articles were conditioned for 24 hours at 23 ° C ± 3 ° C and 55% ± 5% relative humidity. The aged aerosol generating articles were ignited with an electric lighter and allowed to burn for a period of 2 minutes. After 2 minutes, the aerosol-generating articles were placed on the stack of Whatman paper sheets for a period of 10 minutes. After 10 minutes, the indicated sheets of Whatman paper were examined. It was found that an aerosol generating article having a ceramic paper layer surrounding a combustible heat source substantially along its entire length did not form a hole in any of the Whatman paper sheets, but formed only a small brown portion in the top sheet of paper. This result shows that due to the presence of the ceramic paper layer surrounding the combustible heat source substantially along its entire length, the surface temperature near the said heat source is reduced.

FIG. 5 is a schematic view of a second embodiment of an aerosol generating article according to the present invention. The aerosol generating article 102 is substantially similar to the aerosol generating article 2 shown in FIG. 1. The aerosol generating article 102 comprises a combustible heat source 103, an aerosol forming substrate 104, a ceramic paper layer 105, and a cigarette paper layer 107, arranged in a manner similar to corresponding components of the aerosol generating article 2 shown in FIG. 1. However, the combustible heat source 103 is a non-continuous heat source. The discontinuous heat source 103 comprises an annular body 115 of carbon material having a channel 116 extending between a distal end and a proximal end. The duct 116 defines a portion of the air flow path through the aerosol generating article and allows air to be drawn from the proximal end of the aerosol generating article through the combustible heat source 103 to the aerosol-forming substrate 104. The ceramic paper layer 105 is spaced from the specified air flow path through the aerosol generating article 102 so so that the air drawn in through the specified air flow path does not come into direct contact with the ceramic paper 105.

Between the proximal end of the combustible heat source 103 and the distal end of the aerosol-forming substrate 104 is a non-combustible, substantially airtight first baffle 106, similar to the first baffle 6 described above with respect to FIG. 1. However, unlike the first baffle 6 described above, the first baffle 106 includes an opening 120 aligned with the channel 116 to allow air from the channel 116 to pass the aerosol-forming substrate 104.

The inner surface of the duct 116 is covered with a non-combustible, substantially airtight second baffle 117. The second baffle 117 isolates the air passing through the duct 116 from the combustible heat source 103 and from the combustion products of the said combustible heat source.

Since the combustible heat source 103 is a non-continuous heat source, the aerosol-generating article 102 does not include air inlets located in the aerosol-generating substrate 104. When the user puffs on the mouthpiece of the aerosol-generating article 102, it is possible to draw ambient air into the aerosol-generating article 102 through channel 116 passing through heat source 103. Air drawn into the interior of the aerosol generating article 102 is allowed to flow along the specified air flow path in the aerosol generating article 102 through the channel 116, the aerosol forming substrate 104, the transfer element, the cooling element and the separating element to the mouthpiece and exit from the mouthpiece for inhalation by the user. The general direction of air flow through the aerosol generating article 102 is indicated by arrows.

It will be appreciated that, in some embodiments, other air inlets may also be provided in the aerosol generating article in addition to said air passage through the combustible heat source.

The specific embodiments described above are intended to illustrate the invention. However, other embodiments may also be proposed without departing from the spirit and scope of the present invention as defined in the claims, and it should be understood that the above-described specific embodiments are not intended to be limiting.

Claims (39)

1. An aerosol generating article containing: aerosol-forming substrate; combustible heat source; at least one layer of ceramic paper surrounding at least a portion of the length of the combustible heat source, said at least one layer of ceramic paper being configured to provide sufficient air flow through this layer so as to allow the combustible heat source to burn substantially unhindered ; one or more air flow paths that allow air to be drawn in through the aerosol generating article for inhalation by a user; and one or more non-combustible, substantially airtight, partitions between the combustible heat source and the aerosol-forming substrate. 2. The aerosol generating article of claim 1, wherein at least one layer of ceramic paper has an air permeability greater than about 4000 (cm ³ / (min * cm ² ). 3. An aerosol generating article according to any one of the preceding claims, wherein said at least one layer of ceramic paper is isolated from said one or more air flow paths such that, in use, air drawn through the aerosol generating article along said one or more air paths flow does not come into direct contact with the specified at least one layer of ceramic paper. 4. An aerosol-generating article according to any one of the preceding claims, wherein the combustible heat source, the aerosol-forming substrate and said at least one layer of ceramic paper are positioned such that the temperature of the aerosol-forming substrate does not exceed 375 ° C during the combustion of said combustible heat source ... 5. An aerosol generating article according to any one of the preceding claims, wherein the ceramic paper comprises from about 50 wt% ceramic to about 100 wt% ceramic. 6. An aerosol generating article according to any one of the preceding claims, wherein the ceramic paper contains silica fibers. 7. An aerosol generating article according to any of the preceding claims, wherein the ceramic paper contains bio-soluble ceramic fibers. 8. An aerosol generating article according to any one of the preceding claims, wherein said at least one layer of ceramic paper has a thickness of from about 0.5 to about 5 mm. 9. An aerosol generating article according to any of the preceding claims, wherein the non-combustible, substantially airtight, baffle between the combustible heat source and the aerosol forming substrate comprises a first baffle that abuts the proximal end of the combustible heat source and / or the distal end of the aerosol forming substrate. 10. An aerosol generating article according to any one of the preceding claims, wherein said one or more air flow paths comprise one or more air inlets located between the proximal end of the combustible heat source and the proximal end of the aerosol generating article such that air can be drawn in into said one or more air flow paths of the aerosol generating article through said one or more air inlets without passing through a combustible heat source. 11. An aerosol generating article according to any one of the preceding claims, wherein said one or more air flow paths comprise one or more air flow paths passing through a combustible heat source, a non-combustible, substantially airtight, partition between the combustible heat source and said one or the more air flow channels further comprises a second baffle located between the combustible heat source and said one or more air flow channels in the combustible heat source. 12. An aerosol generating article according to any one of the preceding claims, further comprising one or more additional layers surrounding at least a proximal portion of a combustible heat source and a distal portion of an aerosol forming substrate, said one or more additional layers comprising at least one of the following: a heat transfer element for transferring heat from a combustible heat source to an aerosol-forming substrate, and a layer of cigarette paper. 13. The aerosol generating article of claim 12, wherein said at least one ceramic paper layer is a radially outer layer overlying at least a portion of said one or more additional layers. 14. A method of manufacturing an aerosol generating product according to PP. 1-13, including the stages at which: dispose of a combustible heat source for heating the aerosol-forming substrate; providing one or more air flow paths that allow air to be drawn in through the aerosol generating article for inhalation by a user; and isolating the combustible heat source from said one or more air flow paths so that, in use, air drawn through the aerosol generating article along said one or more air flow paths does not come into direct contact with the combustible heat source; and surrounding at least a portion of the length of the combustible heat source with at least one layer of ceramic paper; wherein said at least one layer of ceramic paper is configured to provide a sufficient flow of air through the layer so as to allow the combustible heat source to burn substantially unimpeded. 15. The method of claim 14, wherein at least one layer of ceramic paper has an air permeability greater than about 4000 (cm ³ / (min * cm ² ). 16. The method of claim 14 or 15, wherein the step of surrounding at least a portion of the length of the combustible heat source with at least one layer of ceramic paper includes the steps of: provide a strip of ceramic paper having opposite ends; wrapping the specified strip around the combustible heat source such that the specified combustible heat source is surrounded by at least one layer of ceramic paper; overlap opposite ends of said strip; and the superimposed ends are bonded to each other to attach the at least one layer of ceramic paper to a combustible heat source. 17. The method of claim 14 or 15, wherein the step of surrounding at least a portion of the length of the combustible heat source with at least one layer of ceramic paper includes the steps of: provide a strip of ceramic paper having opposite ends; applying a layer of adhesive to one side of said strip at least at each of said opposite ends; position the specified strip so that the specified layer of adhesive is facing the combustible heat source; wrapping said strip around a combustible heat source so that said combustible heat source is surrounded by said at least one layer of ceramic paper; provide the abutment of the opposite ends of the specified strip without overlapping these opposite ends; and attach the specified strip to the combustible heat source using the specified layer of adhesive.

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